Common sanding jobs calling for considerable detail work or access to small confined areas, or for the sanding of contoured surfaces, will often require that the surfaces be hand sanded. Heretofore, hand-held sanding devices for this purpose consist essentially of a sanding block for holding conventional sandpaper wrapped over the block. By using a sanding block as a sandpaper holder, hand-applied sanding forces on the sandpaper can be increased and more evenly distributed.
The difficulty with the above-mentioned prior sanding devices is the necessity of installing or wrapping a separate piece of sandpaper around the device. This installation or wrapping process presents some inconvenience to the user. For example, if the paper is improperly installed, it is susceptible to falling off. Also, the device requires the purchase of separate sheets of sandpaper that is a further inconvenience in terms of the amount of supplies needed.
U.S. Pat. No. 4,887,396 (Lukianoff) discloses a hand-sized sanding device that eliminates the need for a separate sheet of sandpaper. The sanding device is provided with its own integral abrasive surfaces that can be manufactured at a sufficiently low cost to be disposable. The sanding device of Lukianoff can be conveniently used off-the-shelf to hand sand a variety of standard, contoured or shaped surfaces, such as trim or molding surfaces, and for projecting into exactly defined areas.
Another type of sanding device is the resilient flexible sanding sponge. Sanding sponges generally include a layer of abrasive particles adhered to a foam backing by a flexible adhesive. One such sanding sponge is commercially available from Minnesota Mining and Manufacturing Company, St Paul, Minn. under the trade designation “Softback Sanding Sponge”. Typically, a user places the backing layer against the palm of his or her hand and rubs the abrasive over a surface to be abraded. The flexible adhesive layer and the foam backing permit the layer of abrasive to conform to the surface being abraded.
While such sanding sponges work quite well to abrade objects having flat surfaces, the foam backing and/or the flexible adhesive layer is often torn when they are used to abrade the intersecting surfaces of projections such as the corners of a table top. Hand pressure on the sanding sponge can cause such a projection to penetrate and tear the backing layer of the sanding, sponge as it is moved over the projection. A sanding sponge with high tear strength backing layer is disclosed in U.S. Pat. No. 6,419,573 (Lise et al.).
One specialty sanding sponge is the corner sanding sponge is a compressible sponge of an open-celled foamed polyurethane. The sponge has first and second planar surfaces that meet at a right angle. The first and second planar surfaces are coated with an abrasive material. The portion of the sponge enclosed between the first and second surfaces includes a grasping means forming an integral portion of the sponge.